title: Genetic structure of Plasmodium falciparum populations across the Honduras-Nicaragua border.
abstract: BACKGROUND
  The Caribbean coast of Central America remains an area of malaria transmission caused by Plasmodium falciparum despite the fact that morbidity has been reduced in recent years. Parasite populations in that region show interesting characteristics such as chloroquine susceptibility and low mortality rates. Genetic structure and diversity of P. falciparum populations in the Honduras-Nicaragua border were analysed in this study.
  
  
  METHODS
  Seven neutral microsatellite loci were analysed in 110 P. falciparum isolates from endemic areas of Honduras (n = 77) and Nicaragua (n = 33), mostly from the border region called the Moskitia. Several analyses concerning the genetic diversity, linkage disequilibrium, population structure, molecular variance, and haplotype clustering were conducted.
  
  
  RESULTS
  There was a low level of genetic diversity in P. falciparum populations from Honduras and Nicaragua. Expected heterozigosity (H(e)) results were similarly low for both populations. A moderate differentiation was revealed by the F(ST) index between both populations, and two putative clusters were defined through a structure analysis. The main cluster grouped most of samples from Honduras and Nicaragua, while the second cluster was smaller and included all the samples from the Siuna community in Nicaragua. This result could partially explain the stronger linkage disequilibrium (LD) in the parasite population from that country. These findings are congruent with the decreasing rates of malaria endemicity in Central America.
authors.affiliation: Instituto de Investigacion en Microbiologia, Escuela de Microbiologia, UNAH, Tegucigalpa, Honduras. gustavo.fontecha@unah.edu.hn.
authors.forename: Nerea
authors.initials: N
authors.lastname: Larrañaga
authors.forename: Rosa E
authors.initials: RE
authors.lastname: Mejía
authors.forename: José I
authors.initials: JI
authors.lastname: Hormaza
authors.forename: Alberto
authors.initials: A
authors.lastname: Montoya
authors.forename: Aida
authors.initials: A
authors.lastname: Soto
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: Fontecha
mesh_terms: D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000235:genetics; D019353:Endemic Diseases; D014644:Genetic Variation; D006721:Honduras; D006801:Humans; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000469:parasitology*; D018895:Microsatellite Repeats; D017720:Molecular Epidemiology; D009527:Nicaragua / Q000453:epidemiology; D010802:Phylogeny; D010963:Plasmodium falciparum / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D016054:DNA, Protozoan